Can-washing machines



C. S. VOLK CAN-WASHING MACHINES Sept. 24, 1963 2 Sheets-Sheet 1 FiledApril 8, 1963 ii-Fl INVENTOR: oed 6.1M

M g -g United States Patent 3,104,407 CAN-WASHING MACS Cecil S. Volk,179 Kings Point Road, Great Neck, N.Y. Filed Apr. 8, 1963, Ser. No.271,203 16 Claims. or. 15-41 My invention relates to machines forwashing garbage cans, milk cans and similar receptacles, and its generalobject is to clean the cans thoroughly for repeated and sanitary use inone continuous and automatic operation.

Other objects are to wash the cans both at their inside and outside withwater that may contain a detergent, a disinfectant or both, to brush thecans at inside and outside, and to direct streams of water toward thebrushes whereby the brushed spots are simultaneously rinsed and dirt isthoroughly removed from them.

Further objects are to arrange an outer and an inner brush so directedtoward each other that they always brush the same par-t of the can wallwhereby strong brushing pressure can be applied without dislocation ofthe can because the pressure of one brush counteracts the pressure ofthe other brush, to rotate the brushes about the can axis while movingthem along this axis and along the can wall whereby the brushes willsuccessively reach all parts of the lateral can wall, and to rotate thebrushes also about an axis perpendicular to this wall whereby theiraction is still more effective.

Another object is to hold the can in upside-down positioin so that thedirty or excessive washing water flows immediately down out of the can,and so that the entire interior of the can is accessible to the brushes.

Still further objects are to produce movements of the brushes andcorresponding movements of the water-ejecting pipes in elfective andsimple manner, and to rotate and shift the brushes together with thesepipes either hydraulically by the washing Water, or mechanically bymotor force, or by hydraulic and mechanical means.

Still other objects are to attain the before mentioned objects with amachine which occupies little space, which can be moved to any placedesired, which allows easy and secure positioning of the can, which canbe easily connected with a Water supply, and which can be easily madeand maintained in well working condition.

Still further objects and advantages will appear from the followingdescription of an exemplifying embodiment of my invention and ofmodifications of this embodiment, from the appended claims and from theaccompanying drawings in which:

FIG. 1 is a partly sectional side view of an illustrative embodiment ofmy invention, the sectionally represented parts being out along the line1-1 in FIG. 2.

FIG. 2 is a cross-section taken along the line 22 in FIG. 1.

FIG. 3 is a side view of a detail of the same embodi ment, seen from theleft side in FIG. 1.

FIG. 4 is a view of another detail, seen in the same direction as FIG.1.

FIG. 5 is a partly sectional side view of the latter detail, thesectionally represented parts being cut along the line 55 in FIG. 4.

'FIG. 6 is a partly sectional bottom view of still another detail, thesectionally represented parts being out along the line 6-6 in FIG. 1.

FIG. 7 is a partly sectional side view of a modified part of theembodiment shown in FIGS. 1 to 6, the sectionally represented partsbeing out along the line 7-7 in FIG. 9.

FIG. 8 is a partly sectional view seen from the left side in FIG. 7,some parts being broken off, the sectionally represented parts being outalong the line 8-8 in FIG. 7.

FIG. 9 is a partly sectional bottom view of modified parts, thesectionally represented parts being out along the line 9-9 in FIG. 7,some parts being broken off.

FIG. 10 is a partly sectional top view of some details of the modifiedpart, the sectionally represented parts being out along the line 1010 inFIG. 7.

All figures are represented on reduced scales, FIGS.

7 7 to 10 on a larger scale than FIGS. 1 to 3, FIG. 6 on a still largerscale and scale.

The embodiment shown in FIGS. 1 to 6 comprises a housing 3 which ispreferably cylindrical and has a lateral door 7 hinged to the housing at8, and provided with a hand knob 9. Two members 11 shaped likeupsidedown Us are afiixed to the bottom of the housing 3 and have fourlegs 12 supporting the housing. The legs 12 may terminate in bearingsfor the axles of wheels 13 whereby the machine can be easily moved toany desired place. At the lower end of the lateral housing wall, anopening is provided in which an outlet pipe 14 is secured. This outletcan be closed by a valve 15 operated by a hand wheel 16.

Means are provided for suspension of a can in the housing and are soarranged that the entire surface of the can, except two tiny spots, isleft free. For example, two somewhat resilient clamps 17 are afiixed tothe inside of the housing top and so positioned that they engage thebottom rim of a garbage can 18 when the latter is inserted in a positionin which the can is upside-down and co-axial with the housing. A centralopening in the bottom of the housing is surrounded by an upward risingsleeve-like part 19 of the housing. This opening is co axial withhousing 3 and can 18.

A tube 21 passes watertightly through the sleeve 19 and has an outerdiameter fitting the inner diameter of the sleeve whereby the tube 21 isrotatable in the sleeve about the axis of the housing and is shiftablein the direction of this axis. A pipe 22 forms an upward extension ofthe tube 21. At its upper end, the pipe 22 has a horizontal continuationwhich comprises a bent part 23 and a substantially straight part 24extending radially with respect to the housing a little less far thanthe inner radius of the can 13. A row of openings 25 is provided in theupper side of the pipe part 24.

A pipe 26 branches off the lower end of the pipe 22 and extends inhorizontal direction farther than the outer diameter of the can 18, thenturns upward and terminates in a horizontally bent part 27 having anoutletopening at its end. The pipe part 23 has also an outlet opening atits free end. These two outlet openings are prefer,- ably positioned atthe same level.

The tube 21 and the pipes 22 and 26 are parts of a water-conveying orconduit system which is horizontally rotatable and vertically shiftable.The pipe 22 forms a conduit of which the vertical direction extendsinside of the position of the can. The pipe 26 forms a vertical conduitin a direction outside of the can position. Thereby, the conduit systemcan rise with these conduits moving aside of and along the lateral canWall.

Two brushes 28, 29 are so connected with the conduit system that theymove with the same. For example, a brush holder 31 has an arm 32 afiixedto the pipe part 27. The brush 28 has a cylindrical stem 33 rotatable ina bore of the holder 31 and secured against excessive axial shift by anut 34 screwed on the end of the stem 33. Similarly, the brush 29 isrotatably carried by a holder 35 which has an arm 36 aifixed to the pipepart 23. Each of these brushes is positioned with its bristles extendinginto contact with the can wall when the conduit system is in raisedpoistion, the bristles of brush 28 contacting the outside and those ofbrush 29 the inside of this wall.

The outlet of the pipe part 27 is directed toward the FIGS. 4 and 5 on astill larger 3 brush 28, and .the outlet of the pipe part 23 toward therush 29. Preferably, each of these brushes has shovels 38 affixed to itsperiphery in the manner of a waterwheel. For example, each brush mayhave six shovels, some of which are omitted in FIGS. 1 and 2 for thesake of clear representation of other details.

Preferably, another brush 30' is afilixed to the conduit system, forexample to the pipe part 24. The brush 30 extends horizontally in radialdirection of the can 18. Bristles of the latter brush extend upward andcontact the bottom of the can brushingly when the conduit system is inits uppermost position. In addition, the brush 3t) may have bristlesextending in radial direction.

A rin -shaped swimmer 39 is positioned in the housing under the pipe 26and preferably affixed to the same.

A bracket 41 is afiixed to the bottom of the housing, extends downwardand has horizontal arms 42, 43 provided with holes which are coaxialwith the tube 21 and threaded to engage an outer screw thread 44 of apipe 4 5 which forms a downward continuation of the tube 21. The thread44- is interrupted by a groove 46 which extends along the pipe 45 and isso slidably engaged by an inner projection of a wheel 47 in known mannerthat the wheel can rotate the pipe 45 without hindering the verticalmovement of the latter. The wheel 47 is secured against verticaldislocation by the bracket arms 42, 43.

The wheel 47 is rotated by a belt or chain 48 which connects this wheelwith the driving wheel -49 of a motor M. This motor may also serve todrive a pump P. Motor and pump may form a compact aggregate mountedunder the bottom of the housing 3.

The pump is supplied with water from any available source through a pipeor hose 51. A detergent or a disinfectant or both may be added to thewater, preferably before the water is fed to the pump; The pump pressesthe water through a hose 52 into the pipe 45 with which the hose isrotatably connected, for example by a coupling 53 of known structure. Ifa water source of sufficient pressure is available, the pump may beomitted and the hose 52 may be directly connected to this source.

The operation of the described machine starts with the conduit system inthe shown, lowermost position. After a can 18 has been firmly secured inthe clamps 17, the door 7 and the valve 15 are closed, and the watersupply is set in motion. The water pressed into the conduit system risesthrough pipe 45, tube 21 and then simultaneously through the pipes 22and 26' from which the water flows through the pipe parts 23, 24 and Z7,and streams out of the openings of these pipe parts.

The water ejected from the conduit system drops and gradually fills thebottom of the housing 3. The rising water level lifts the swimmer 39 andthereby the conduit system whereby the pipes 22 and 26 rise along thelateral wall of the can 18, the pipe 22 entering the interior of thecan, and the pipe 26 moving outside of the same while the brushes 28 and29 move in contact with the can wall. At the same time, the reaction ofthe streams flowing out of the pipe ends 23 and 27 causes the conduitsystem to rotate due to the fact that the directions of the outlets ofthese pipes do not pass through the rotary axis of this system but havecomponents tangential to the rotation of this system.

In addition to or instead of these hydraulic means, mechanical means maybe used to enforce the rising and rotary movement of the conduit system.Obviously, various mechanical devices could be used for this purpose inaddition to a motor M. In the shown embodiment, the mechanical meanscomprise a motor wheel 49, a chain 48 driven by this wheel, a wheel 47rotated by this chain, the pipe 45 rotated by the wheel 47, and thebracket 41 in the threaded holes of which the pipe 45 screws upward whenrotated.

If the movement of the conduit system is to rely only on the hydraulicmeans, the mentioned mechanical means, except the motor, may be omitted,and the coupling 53 4- may directly connect the hose 52 with the tube21. If the movement of the conduit system is to rely only on themechanical means, the swimmer 39 may be omitted. In

any case, the pump may be omitted and the hose 51 directly connectedwith the coupling 53 if the pressure of the water source is sufficientlyhigh. The simultaneous use of both, hydraulic vand mechanical means,results in a particularly strong and reliable drive of the circuitsystent.

The brushes rise with the conduit system and brushthe lateral wall ofthe can 18 from the open can side up. The water streaming from the pipeends 27 and 23 keeps the brushes clean, washes the brushed spots of thecan, and also hits the shovels 38, causing the brushes to rotate intheir holders in addition to their rotation with the conduit system.This results in a strong cleaning action;

is aflfixed to the conduit system whereby the swimmer rotates and stirsthe water gathered at the housing bottom. The stirring prevents the dirtfrom settling down sothat the dirt will readily flow out when the valveis opened.

This valve vl5 and the pipe 14 are of relatively large'width wherebydirt can easily pass through them.

When the conduit system has reached its uppermost position, the washingof the can is finished. Then, the.

valve 15 is opened and, if mechanical moving means have been used, thesame are reversed whereupon the conduit system returns to the shownposition. The can isthen taken out of the housing through thetemporarily opened door 7. If desired, the Water supply may beresumed'with the valve 15 remaining open in order to clean the house ingbottom thoroughly before another can is inserted for being washed.

FIGS. 7 to 10 illustrate modifications of the embodi- The partspositionedunder the housing are omitted in these figures and may mentdescribed in the foregoing.

be identical to the parts positioned under the housing in the firstdescribed embodiment.

The modified parts comprise a housing 55 which is similar to the housing3 and has a door 56 provided with a,

hand knob 57 and hinged to the housing 55 at 58. In

an opening of the lower end of the lateral housing wall,

an outlet pipe 59 is affixed. A valve 61 is incorporated in the pipe 59.The valve 61 is operated by a stem 62 provided with a flange 63. Aspring 64 ,is positioned between this flange and the valve and holds thevalve ordinarily in closed condition.

The valve 61 can be opened 65 contacting the upper end of the stem 62,having \another arm 66 reaching into the housing 55 through aslot in thelateral housing wall, and having a hinge axle 67 rotatable in bores oftwo projections 68 of this wall. When the lever 65, 66 is turned in thedirection clockwise in FIG. 7, the arm 65 presses the stem 62 downagainst the pressure of the spring 64, thereby opening the valve 61,until the edge 69 of the arm 65 snaps over the edge 70 of the stem. Inthis position, the stem 62 contacts the surface 71 of the arm 65 and isthereby prevented from moving upward as in the shown position in whichthe valve is closed. The engagement of the snapped-over edges 69 and 70prevents return of the lever into the shown position whereby the valveremains open until this engagement is released by a slight depression ofthe stem 62 by hand.

A tube 72 passes fittingly, rotatably and shiftably through a centralopening of the housing in the same manner as the tube 21 of the firstdescribed embodiment. A bar 73 is afiixed to the upper end of the tube'72' and extends horizontally to a point positioned under the armby alever having an arm amtm 66. When the tube rises and approaches itsuppermost position, the bar 73 contacts the arm 66 and operates thelever 65, 66.

The motor M (FIG. 1) is operated by an electric circuit 74 of which apart is schematically shown in FIG. 7. This circuit part contains aswitch having one arm 75 afiixed to the lever 65, 66 and another arm 76affixed to a projection 77 of the housing 55. When the lever 65, 66 isturned as described before, the switch 75, 76 opens, interrupting thecircuit 74 and thereby arresting the motor M. The switch remains in opencondition until the lever 65, 66 is returned into the shown position.

A screw 78 co-axial with the tube 72 passes through a threaded bore ofthe top of the housing 55 and has a top handle 79. A double clamp 81 isconnected with the lower end of this screw and formed to engage thebottom rim of a can 82 similarly as the clamps 17 engage the can 18. Byscrewing the screw 78 more or less into the housing, the height of theclamp 81 can be adjusted whereby cans of various heights can be properlysuspended in the housing. A counter-nut 83 serves to secure the screw 78in adjusted position.

The tube 72 is a part of a conduit system which further comprises pipes84 and 85. The pipe 84 forms an upward continuation of this tube. Aflexible conduit or hose 86 is attached to the pipe 84, forms a furtherup ward continuation and has an upper end attached to a pipe 87. Thepipe 85 extends from the tube 72 horizontally to a point farther fromthe housing axis than the largest diameter of the can 82, then is bentand terminates in a rising part to which a hose 88 is attached. Theupper end of this hose is attached to a pipe 89. The vertical directionof the conduit 84, 86, 87 extends inside of the can position. 85, 88, 89extends outside of this position.

An outer brush-holder 91 similar to the shoulder 31 is amxed to the pipe89 by a connecting bent arm 92, and another identical inner brush holderis connected with the pipe 87 by a bent arm 93. These brush holderscarry rotatable brushes 94 and 95. The structure of these holders andbrushes and the position of the latter relative to each other andrelative to the can wall may be identical to structure and position ofthe holders 31, 35 and the brushes 28, 29. The waterwheel-like shovelsof the brushes are omitted in FIGS. 7 to 9 for the sake of clearrepresentation of other parts.

The :brushes 9'4 and 95 are supported by a member 96 so that they canmove later-ally without changing their mutual position. For example,this member has a lower end hinged by a horizontal axle 97 to two arms98 which are afiixed to the tube 72. From this lower member end, twoarms of the member branch, extend upward and have upper ends one ofwhich is affixed to the brush holder 91 while the other is aflixed tothe other brush holder.

A swimmer 99 is positioned in the housing 55 under the arms 73 and 98and operated in the same manner as the swimmer 39.

The pipe 89 has an extension which comprises a part 16-1 with an outletopening at its end. This part is so bent that this outlet points towardthe brush 94. Another part of this extension 102 is first directedoutward with respect to th housing axis, then upw amd and then ininwardly declining direction, and terminates in an outlet 193. When theconduit system has risen so far that the outlet 183 is higher than thebottom of the can 82, the stream from this outlet washes the outside ofthe can bottom, first near the periphery of this bottom, then graduallyfarther to the center which is washed when the conduit system is in itsuppermost position. The pipe 87 has a horizontal extension 164 providedwith openings 105 at its upper side for washing the inside of the canbottom, and with an end outlet 186 directed toward the brush 95.

The vertical direction of the conduit Means are provided for brushingthe inside of the can bottom when the conduit system is near itsuppermost position. These means are preferably so arranged that they canpass through the neck of a can of varying diameter. For example, a brush107 has a forked lower end 108 hinged to the inner brush holder so thatthe brush 107 can turn in a vertical plane. A spring 109 afiixed to thesame brush holder contacts the brush 107 and holds the same ordinarilyin the inclined, upward extending position shown. When rising of theconduit system brings the upper end of the brush 107 into contact withthe can bottom, this brush is gradually turned down until, in the.uppermost position, this brush extends horizont-ally and brushes the canbottom. Preferably, the upper end of the brush 107 is formed by a roller111 rotatably connected with the main part of this brush whereby thecontact between brush and can bottom is changed from a sliding to arolling contact, and the movement of the brush 107 is facilitated.

The described modified embodiment comprises details which adapt themachine to washing of cans of varying diameter, for example of milk cans82, but also comprises details which obviously may be incorporated inthe first described embodiment without such adaptation. The modifiedembodiment is operated as follows: While the conduit system is in theshown lowermost position and the circuit 74 is interrupted either byopen position of the switch 76, 77 or otherwise, a can 82 is insertedthrough the temporarily opened door 56 in the housing in upside-downposition so that this can is firmly held by the clamp 81. The height ofthis clamp is then so adjusted that the lower rim of the can reachesinto the narrow space between the brushes 94 and while the conduitsystem is so held that this space is in line with this rim. The can hasthen the position shown in the drawing. The valve, if not alreadyclosed, is then closed by depression of the stem 62, allowing the lever65, 66 to turn into the shown position. The circuit '74 is closedwhereby the motor M starts.

The conduit system is then rotated and raised by hydraulic or mechanicalmeans or by both in the same manner as in the first described embodimentwhile the rising brushes 94, 95 are guided by the lateral wall of thecan 82, and the member 96 slightly swings about the axis of the axle 97.Thereby the lateral can wall is brushed and washed in a mannercorresponding to the first described embodiment.

During the last period of the rising movement of the conduit system, thecan bottom is washed in the manner described before. When the conduitsystem approaches its uppermost position, the bar 73 operates the lever65, 66 in the manner described before. Thereby the valve 61 and theswitch 76, 77 are opened, terminating the washmg operation.

I desire it understood that my invention is not confined to theparticular embodiment and its modifications shown and described, thesame being merely illustrative, and that my invention may be carried outin other ways within the scope of the appended claims without departingfrom the spirit of my invention as it is obvious that the particularembodiment and its modifications shown and described are only some ofthe many ways that may be employed to attain the objects of myinvention.

Having described the nature of my invention, what I claim and desire toprotect by Letters Patent is:

l. A can-washing machine comprising a housing; means for suspension of acan in upside-down position in said housing; a conduit system comprisinga tube co-axial with the position of said can and passing fittingly,rotatably and vertically shiftably through the bottom of said housing,said system further having two conduits forming extensions of said tubeand extending vertically upward, the vertical direction of one of saidconduits extending outside of the position of said can and the verticaldirection of the other conduit extending inside of the latter positionwhereby said system can rise with one of said conduits moving outsideand along the lateral wall of said can and the other conduit inside andalong said wall; two brushes connected with said system and, when saidconduits rise along said can wall, contacting said wall with theirbrushing sides, one brush from the outside and the other from the insideof said wall; one of said conduits having an outlet directed toward oneof said brushes and the other conduit having an outlet directed towardthe other brush; and means moving said system rotatab-ly about the axisof said tube and vertically in the direction of said axis.

2. A machine according to claim 1 in which machine said brushes aredirected toward each other whereby their contacts with said wall are onboth sides of the same wall part.

3. A machine according to claim I, further comprising a brush holderafiixed to said system and carrying one of said brushes rotatably; andshovels afiixed to said latter brush in waterwheel-like arrangement.

4. A machine according to claim 1, further comprising a pipe forming anextension of said system, extending, in raised position of said system,in said can in substantially radial direction of the latter, and havingoutlet openings directed upward whereby said latter openings aredirected toward the bottom of said can.

5. A machine according to claim 1, further comprising 7 another brushafiixed to said system, extending, in raised position of said system, insaid can in substantially radial direction of the latter, and havingbristles extending upward farther than the parts of said system enteringsaid can whereby said bristles, in uppermost position of said system,contact the bottom of said can.

6. A machine according to claim 1 in which machine said conduit outletshave directions having components tangential to the rotation of saidsystem whereby the reaction of streams flowing out of said outlets tendsto rotate said system.

7. A machine according to claim 1 in which machine said moving means arehydraulic and comprise a swimmer positioned in said housing a part ofsaid system whereby water gathering in said housing tends to raise saidswimmer and said system.

8. A machine according to claim 1 in which machine said moving means arehydraulic and comprise a swimmer afiixed to said system whereby watergathering in said housing tends to raise said swimmer and said system,and the swimmer rotates with said system, thereby stirring the gatheredwater.

9. A machine according to claim 1 in which machine said moving means arehydraulic and comprise a motor, a pump driven by said motor, and a hoseconnecting said pump with said conduit system whereby water can be fedto said system under high pressure.

10. A machine according to claim 1 in which machine said moving meansare mechanical and comprise a motor drivingly connected with saidsystem.

11. A machine according to claim 1 in which machine said moving meansare mechanical and comprise a pipe forming a downward extension of saidtube and having a threaded and longitudinally grooved outside, a bracketaffixed to said housing and having a threaded hole screwingly engaged bysaid latter pipe, a wheel having an inner projection slidably engagingsaid groove, and a motor drivingly connected with said Wheel.

12. A machine according to claim 1 in which machine said moving meanscomprise hydraulic and mechanical means.

13. A machine according to claim 1 and further comprising a pipe formingan extension of said system and havingan outlet positioned outside ofthe position of said can, higher than said brushes and directeddownwardly and inwardly inclined with respect to said housing wherebywater streaming from said latter pipe will 'hit the upper side of thecan bottom when said latter pipe is raised higher than said bottom.

14. A machine according to claim 1 and further comprising ianother brushextending within the position of said can, a horizontal axle connectingone end of said other brush rotatably to said system, and a springafiixed to said system and holding said other brush in a positionextending obliquely upward from said axle whereby said brush is presseddown against the pressure of said spring into horizontal position whenthe upper end of said latter brush hits the can bottom, said other brushhaving bristles extending upward in said horizontal position wherebysaid bristles contact the can bottom when said system is in itsuppermost position;

15. A machine according to claim 1 and further coniprising an outletpipe afiixed to said housing, a valve incorporated in said pipe, aspring holding said pipe ordinarily in closed condition, a leverrnovably connected with said housing, having an arm reaching into saidhousing,

and being operatively connected with said valve, and a bar afiixed tosaid system and contacting said lever arm when said system approachesits uppermost position whereby said lever is opera-ted and said valve isopened when said system is in its uppermost position.

16. A machine according to claim 1 and further com- A prising a motorforming a part of said moving means, an'

electric circuit operating said motor, a switch for closing and openingsaid circuit, a lever movably connected with said housing, operativelyconnected with said switch and ordinarily holding said switch incircuit-closing position,

said lever having an arm reaching into said housing, a bar afilxed tosaid system and movably contacting said lever arm when said systemapproaches its uppermost position whereby said lever is operated andsaid switch interrupts said circuit when said system is in its uppermostposition.

References Cited in the file of this patent UNITED STATES PATENTS

1. A CAN-WASHING MACHINE COMPRISING A HOUSING; MEANS FOR SUSPENSION OF ACAN IN UPSIDE-DOWN POSITION IN SAID HOUSING; A CONDUIT SYSTEM COMPRISINGA TUBE CO-AXIAL WITH THE POSITION OF SAID CAN AND PASSING FITTINGLY,ROTATABLY AND VERTICALLY SHIFTABLY THROUGH THE BOTTOM OF SAID HOUSING,SAID SYSTEM FURTHER HAVING TWO CONDUITS FORMING EXTENSIONS OF SAID TUBEAND EXTENDING VERTICALLY UPWARD, THE VERTICAL DIRECTION OF ONE OF SAIDCONDUITS EXTENDING OUTSIDE OF THE POSITION OF SAID CAN AND THE VERTICALDIRECTION OF THE OTHER CONDUIT EXTENDING INSIDE OF THE LATTER POSITIONWHEREBY SAID SYSTEM CAN RISE WITH ONE OF SAID CONDUITS MOVING OUTSIDEAND ALONG THE LATERAL WALL OF SAID CAN AND THE OTHER CONDUIT INSIDE ANDALONG SAID WALL; TWO BRUSHES CONNECTED WITH SAID SYSTEM AND, WHEN SAIDCONDUITS RISE ALONG SAID CAN WALL, CONTACTING SAID WALL WITH THEIRBRUSHING SIDES, ONE BRUSH FROM THE OUTSIDE AND THE OTHER FROM THE INSIDEOF SAID WALL; ONE OF SAID CONDUITS HAVING AN OUTLET DIRECTED TOWARD ONEOF SAID BRUSHES AND THE OTHER CONDUIT HAVING AN OUTLET DIRECTED TOWARDTHE OTHER BRUSH; AND MEANS MOVING SAID SYSTEM ROTATABLY ABOUT THE AXISOF SAID TUBE AND VERTICALLY IN THE DIRECTION OF SAID AXIS.